(Revised Abstract) DESCRIPTION (provided by applicant): The Experimental Mouse Shared Service (EMSS) completes in vivo testing in small animal models prior to clinical evaluation in order to confirm the antitumor and/or preventive activity and tolerance of various agents. The EMSS's purpose is to provide investigators at the AZCC with technical and scientific expertise in experimental mouse models, with an emphasis on severe combined immune deficiency (scid) mouse human tumor models. The specific objectives of the EMSS include the following: Maintaining the University of Arizona scid mouse colony to ensure necessary numbers of scid mice for AZCC investigators; Acquiring and utilizing other mouse strains as needed for experiments by AZCC investigators; Aiding in the design of in vivo experiments; Performing expert and consistent mouse experiments. The EMSS provides consistent, quality procedures within and among mouse experiments to ensure accuracy in experimental results. Special expertise includes tail vein injections, orthotopic (i.e., mammary fat pad) injections and various survival surgery techniques, intratumoral injections, oral gavage, and blood sampling by retro-orbital puncture. The EMSS benefits AZCC investigators by providing a cost-effective mechanism for completing in vivo mouse experiments utilizing highly trained and experienced technicians, allowing for consistent procedures and therefore a decreased chance of error. The EMSS continues to expand its services in a very cost effective and efficient manner.